Just a reminder. You miss capturing their stats in your video.Read this:

Recording Tips [IMPORTANT]Unlike the original fight replays, we cannot see the stats of both fighters. You may want to mouseover both fighters at the start or the end of the fights, so the recording software can screenshot their stats too!

If you leave the info about the level of those brutes, at least we can use the tool to check their stats.

About the bug, you get high damage because you hit your opponent with fierce brute. Fierce brute helps boost your damage.